Sand-blast apparatus.



PATENTED FEB. 21, 1905.

APPLICATION FILED MAY 12. 1904.

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I I z 7 55% I W Niih' STATES Patented February 21, 1905.

ATENT Car es.

JOHN D. MURRAY, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNEASSIGNMENTS, TO INTERNATIONAL SAND BLAST COMPANY, A CORPO- RATION OFCALIFORNIA.

SAND-BLAST APPARATUS SPECIFICATION forming part of Letters Patent N0.783,218, dated February 21, 1905.

Application filed May 12, 1904. Serial No. 207,705.

To all whmn it may concern:

Be it known that I, J OHN D. MURRAY, a citizen of the United States ofAmerica, residing at San Francisco, county of San Francisco, and Stateof California, have invented certain new and useful Improvements inSand-Blast Apparatus; and I hereby declare the following to be a full,clear and exact description of the same, reference being had to theaccom: panying drawings, forming a part of this specification.

This invention relates to certain applications of the sand-blast andimprovements therein.

My improvement consists in driving the sand or abrading material bymeans of air and.

water, the latter entrained by the air as it passes through thedistributing-pipe, preferably at some point near the receiver, fromwhere the air is supplied under pressure, and also consists in devicestoregulate the pressure on and the water admitted to the air-conductingpipe and other accessories, as shown in the drawings herewith andforming a part of this specification.

The object of my improvement is to avoid dust caused by the applicationof sand-blast in confined places, as in the holds of ships, to keep thesand comparatively dry until its impingement and to intensify the effectonobd urate oxidized surfaces by the greater weight of the sand andwater combined. To this end I construct sand-blast apparatus asillustrated by the accompanying drawings, that form a part of thisspecification.

Figure I is a vertical section through a sand-blast apparatus embodyingmy improvements; Fig. II, an enlarged longitudinal section through anozzle for applying the sand, and Fig. III an enlarged section through athrottling-valve such as is" employed to regulate the quantity of sandemployed.

In the application for abrading purposes by a blast of air the efiectproduced, especially on oxidized metallic surfaces, is greatest when thesand is dry; but the dust produced by the operation, especially in theholds of ships and other confined places, is disagreeable to workmen,also is injurious to health by reason of the flying particles inhaled.Steam or saturated air as a means of conveying and applying the sandprevents dust, but at the same time diminishes the abrading effect ofthe sand. It is, however, discovered that water introduced in theair-conducting pipe is carried forward by entrainment in the form ofglobules and is not atomized until it impinges on the surfaces beingabraded or treated. Consequently the effect of the sand remains nearlythe same as when used dry, but the dust that would otherwise rise fromthe surfaces is saturated with the atomized water and prevented. This isthe object of my invention, carried out by means now to be described.

Referring to the drawings, 1 is a receiver filled with air underpressure supplied through a pipe 2; 3, an extension of the receiver 1,forming a dry chamber for the air'coming from receiver 1, which is oftenloaded with moisture of condensation, also forms a convenient structureto which one or more sandejecting nozzles 4 can be attached.

5 is a superposed sand-tank provided with a conical bottom 7 and severalconveying outlets 8, corresponding to the number of sand-ejectingnozzles 4: that are to be employed (commonly two or more) in operatingon marine vessels, a purpose to which my improved apparatus .isespecially adapted.

The nozzles 4c and 9 are adapted to receive the conducting pipes or hose1() and 12, that connect, respectively, to the main nozzle 6 and leadfrom dry chamber 3, sand-tank 5, and the air-receiver 1. i

13 is a water-tank preferably placed within the air-receiver 1 andsubjected to pressure by means of a communicating pipe 14, provided witha stop-valve 15, that can be employed to regulate the pressure. The tankis filled through the nozzles 17 from some source under pressure, as inthe case of city service or by a force-pump. I/Vater from the tank 13passes through a valve 18 and nozzle 19 into the air-current, escapingthrough the valve 21, and is entrained thereby and carried through thehose or pipe 12 to the main nozzle 6 in the form of spray or globuleswithout saturating the air to an extent that wets the sand before itsdischarge from the nozzle 6 and impingement on the surface being abradedor cleaned.

The quantity of sand admitted to the hose or pipe 10 is regulated by thescrew-valve 20,

(shown enlarged in Fig.IlI,)that when screwed inward into the seat 22closes the passage 23. The sand is blown by the blast-nozzles 25 throughthe chamber 27 into the pipe or hose 10, the former having an elasticlining 28 to prevent abrasion by the sand. A similar lining 29 is placedin the main nozzle 6, as shown in Fig. 11, as described and claimed inmy copending application, Serial No. 179,080, for improvements insand-blast apparatus. The

the dust, preventing that from rising and floating in the air.

Having thus described the nature and objects of my improvements, what Iclaim as new, and desire to secure by Letters Patent, is

In sand-blast apparatus, a receiver containing air under pressure, achamber containing sand or other abradingsubstance,flexible pipes orhose connecting from these vessels to an ejecting-nozzle, means toregulate the quantities of air and sand respectively, a water-inlet andmeans to supply water to the air-conductingpipe or hose and means toregulate the amount of water supplied thereto, combined and operatingsubstantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN D. MURRAY.

Vitnesses:

JNo. A. Maenn, HENRY P. DIMOND.

